• 제목/요약/키워드: Ordinary Portland Cement

검색결과 605건 처리시간 0.03초

조강슬래그시멘트를 이용한 콘크리트의 기초물성에 관한 연구 (A fundamental Study on the properties of Concrete by using the Rapid Hardening Blast Furnace Slag Cement)

  • 김진춘;최광일
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1995년도 봄 학술발표회 논문집
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    • pp.72-77
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    • 1995
  • Blast-furnace slag cement has been used widely as a structural material due to the latent hydraulicity of granulated ground blast furnace slag(GGBS)for a long time as The wall as ordinary portland cement. In this study, based on the fundamental investigation on the high strength and high durable concrete using the high fineness GGBS the following remarks can be made. 1) The average desired strenth of concrete is Or=600~800kg/$\textrm{cm}^2$. 2) The above high strength concrete using the high fineness GGBS is more workable than those using only OPC. 3) The adiabatic temperature and drying shringkage decrease, so the density and resistance to sea water attack increase as results. 4)The unit cement content and unit air entrained admixture at the same desired strength of concrete decrease, so the economical high strength concrete can be manufactured from using the high fineness GGBS.

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플라이애시 및 실리카흄을 사용한 고강도유동화 콘크리트의 공학적 특성에 관한 실 험적 연구 (제 2보. 경화콘크리트의 공학적 특성 검토) (An Experimental Study on the Engineering Properties of High Strength Flowing Concrete Using Flyash and Silicafume (Part 2. Engineering Properties of Hardened concrete))

  • 김진만;이상수;김규용;김무한
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1995년도 봄 학술발표회 논문집
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    • pp.84-87
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    • 1995
  • Production of high strength concrete requires a low water-cement ratio and this leads to the high cement content. Mineral admixture like fly ash(FA) is often cheaper than ordinary portland cement(OPC) and this factor in combination with possible improvement in workability and moderation of the heat evolution of the cement-rich mixes tends to encourage its use. The other mineral admisture that its use has been widly advocated is silica fume that increases compressive strength due to its pozzolanic reaction. The objective of this study is to assess the contribution of mineral admixtures(FA, SF) to the workability and the strength of concrete with low water-binder ratios. In this experimental study that investigates and analyzes the properties of fresh concrete. it is presented that using admixtures like flyash and silica fume as binding material increases properties of high strength flowing concrete having very low water cementitious ratios of 0.25 and 0.30.

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삼성분계 시멘트를 사용한 콘크리트의 내구성 (Durability of Concrete Using Ternary Blended Cement)

  • 심은철;배수호;박광수;이준구;임병탁;하재담
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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    • pp.78-81
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    • 2003
  • Recently, physical properties of concrete containing ternary blended cement were actively researching to develop durability, mobility, and atc. as well as strength increase of concrete. In this study, durability of concrete such as the resistance against chloride ion penetration, rebar corrosion, freeze and thaw, and sulfate were researched for concrete containing ordinary portland cement(OPC) and ternary blended cement(TBC), respectively. For this purpose, concrete specimens containing OPC and TBC, respectively, were made for 37.5% of W/C, and then various durability experiments described above were carried out. As a result, it was observed from the test that concrete containing TBC showed excellent durability than concrete containing OPC.

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광물혼화재가 혼합된 시멘트 페이스트 시스템의 레올로지 특성에 관한 연구 (A Study of Rheological Properties on Cement Paste System Mixed with Mineral Admixtures)

  • 박대효;노명현;박춘근
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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    • pp.505-508
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    • 2003
  • The rheological properties of cement paste system mixed with mineral admixture for the purpose of increasing the strength and improving durability and rheology of concrete were investigated. The results were as follows: The rheological properties of one-ingredient paste system were improved with increasing the dosage of superplasticizer. For two-ingredients paste system, increasing the replacement rate of BFS(blast furnace slag) and FA(fly ash), the yield value and plastic viscosity were decreased compared with non-replacement. In the OPC(ordinary portland cement)-SF(silica fume) system, increasing the replacement rate of SF, the plastic viscosity and yield value increased linearly. In three-ingredients paste system, both OPC-BFS-SF and OPC-FA-SF system, the rheological properties were improved compared with the only replacement of SF. Both two- and three- ingredients paste system, the rheological properties using BFS were improved more than FA.

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Effect of elevated temperature on physico-mechanical properties of metakaolin blended cement mortar

  • Morsy, M.S.;Rashad, A.M.;El-Nouhy, H.A.
    • Structural Engineering and Mechanics
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    • 제31권1호
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    • pp.1-10
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    • 2009
  • An experimental investigation was conducted to evaluate the performance of mortars with and without Metakaolin (MK) exposed to elevated temperatures $200^{\circ}C$, $400^{\circ}C$, $600^{\circ}C$ and $800^{\circ}C$ for two hours. The binder to sand ratio was kept constant (1:5.23). The ordinary Portland cement (OPC) was replaced with MK at 0%, 5%, 10% 20% and 30%. All mixtures were designed to have a flow of $94{\pm}5%$. The compressive strength of mortars before and after exposure to elevated temperature was determined. The formation of various decomposition phases were identified using X-ray diffractometry (XRD) and differential thermal analysis (DTA). The microstructure of the mortars was examined using scanning electron microscope (SEM). Test results indicated that MK improves the compressive strength before and after exposure to elevated temperature and that the 20% cement replacement of MK is the optimum percentage.

고로슬래그 시멘트를 사용한 인터로킹 블록의 특성에 관한 연구 (A Study on the Properties of Inter-Locking Block Using Blast-Furnace Slag Cement)

  • 이상태;이대주;신병철;김진선;권상준;한천구
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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    • pp.203-206
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    • 1997
  • In this paper, the properties of Interlocking block contained blast furnace slag cement are compared with that with O.P.C.(ordinary portland cement) and are analyzed under various mix proportions and the dosage of AE agent. According to the experimental results, compressive strength and flexural strength of interlocking block with blast furnace slag cement are lower than that with OPC. Also the strength and the ratio of absorption decrease with higher dosage of AE agent. although interlocking block with OPC has better performance than that of blast furnace slag in the side of quality, it is worth while to use the blast furnace slag as materials of interlocking block considered the side of recycling of resources and economy.

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Physical/Chemical Characterization of Ordinary Portland Cement/Ground Granulated Blast Furnace Slag Pastes Containing Low Carbon Steel as Reinforcements

  • Hwang, Jin-Ha
    • 한국재료학회지
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    • 제13권2호
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    • pp.94-100
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    • 2003
  • The interface between low carbon steel and blended cement pastes containing slag was investigated using impedance spectroscopy. In addition, the pastes were characterized by several analytical methods (XRD, EDX, electrode potential, pH and ICP). The electrical behavior of the interface in the blended slag systems is correlated to its corresponding pore solution chemistry and the products present in the interface. Passivation occurred at the paste/steel interfaces, in cement pastes up to containing from 0 to 75% slag content. 100% slag paste induced corrosion of the low carbon steel, which could be explained by the influence of sulfur on the system.

알칼리활성화 슬래그-레드머드 시멘트 모르타르의 흡수계수가 백화발생에 미치는 영향 (Effects of Moisture Absorption Coefficient of Alkali-Activated Slag-Red Mud Cement on Efflorescence)

  • 강혜주;김병기;김재환;강석표
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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    • pp.130-131
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    • 2016
  • In this study, moisture absorption coefficient and efflorescence properties of Ordinary Portland cement and alkali-activated slag cement mortar were assessed according to their red mud substitution ratio. Tests were conducted to determine the cause of efflorescence, which is a significant obstacle to the recycling of red mud as a sodium activator in alkali-activated slag cement, and to find a method to control efflorescence.

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Al/Ca+Si 비에 따른 시멘트 페이스트의 염화물 고정에 관한 실험적 연구 (The Experiment Study on Chloride Binding of Cement Paste According to The Al/Ca+Si Ratio)

  • 이윤수;이한승
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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    • pp.51-52
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    • 2016
  • This paper researches the Chloride Binding of Cement Paste according to the Ca/Si and Ca/Al Ratio. The mechanisms of chloride ion binding are not completely known, although it is believed that Alumina contents in cementitious system have an important role. For changing cement paste composition, Ordinary Portland Cement(OPC) paste is substituted by Granulated Ground Blast Slag(GGBS). With increasing the ratio of GGBS substitution(Thus alumina contents is increasing), The chloride binding capacity has a tendency to increase of binding chloride ion capacity.

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시멘트 경화체 중에서의 C1-의 확산과 세공용액의 pH에 미치는 혼화재의 영향 (Influence of Blending Materials on C1- Diffusion and pH of Pore Solution in Cement Pastes)

  • 김남중;최상흘;정재동;한기성
    • 콘크리트학회지
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    • 제4권1호
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    • pp.97-106
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    • 1992
  • 보통 포틀랜드 시멘트에 수쇄고로 슬래그, 플라이 애쉬, 실리카흄 등을 치환첨가한 시멘트 페이스트 경화체를 통한 C1-이온의 겉보기 확산계수를 구하고 경화체에서 추출한 세공용액의 C1-이온의 결합능력을 구하였다. C1-이온의 확산계수는 W/C의 증가에 따라 증가하였으며, 혼화재를 치환첨가한 경우 감소하였다. 세공용액의 C1-이온의 농도 및 OH-이온의 농도도 혼화재의 첨가로 감수하였다.